The research behind DDL

Academia and industry working in collaboration 

It seems obvious to say that daylight makes us humans feel good. But how do you explain something that “you just know”? Double Dynamic Lighting is based on a research project at Aalborg University in Copenhagen, as part of a prestigious collaboration between some of the leading companies in the lighting sector: Tridonic, iGuzzini, Fagerhult and Zumtobel. Our common objective was to develop and scientifically validate guidelines for how to effectively combine electric lighting with daylight in everyday life.  

Simplicity is not easy 

Daylight is an extremely complicated natural phenomenon, but one which we humans experience as very simple and natural. And that is precisely why the research process is complex. The thing that makes daylight so unique is the fact that it is dynamic. It is constantly changing in strength and character, both over the course of the day and in relation to the weather. Daylight is almost infinite in its variations, and it is also this dynamism that affects us so much. The first step in the study was therefore to clarify the actual qualities of dynamic daylight and then translate them into commonly occurring parameters within lighting design.  

Tests in light laboratory 

Once all the “daylight parameters” were in place, the researchers built a light lab resembling an ordinary office workplace. Here, the test subjects were placed in four different environments, with a range of variations in the form of warm and/or cold light as well as direct or indirect light. In order to supplement the qualities of the daylight with dynamic electric lighting in real time, a daylight scanner was used. Using information regarding the nature of the incident daylight, the light in the test environments was regulated: the colour temperature as well as the variation in the intensity of the direct and indirect light. If the sky outside was overcast, for example, the dynamic electric lighting could be controlled to compensate for the limited incident daylight. The test subjects were also exposed to light environments in which the electric light was completely static. 

Better comfort with dynamic light 

The test subjects then had to describe how they perceived the various light environments and the atmosphere these created. Their answers were reported both on forms and through interviews. In addition, the researchers had identified words that the test subjects could choose from to describe their feelings. It became apparent that the test subjects considered their visual comfort to be higher when they were able to work in dynamic electric light that complemented the incident daylight. They also described the dynamic lighting as “comfortable”, “motivating” and “energising”.  One of the test subjects described the experience as follows: “It feels as though the daylight and the light in the room are merging somehow. Just as if the weather has made its way into the room and been projected into it.” 

A little piece of the sky 

It is impossible to “manufacture” an electric light that is completely identical to natural light, of course, yet the study demonstrated the potential to create various stimulating light scenarios that we have borrowed from daylight. And so that’s what DDL is: using sensors and luminaires that create dynamic electric lighting with variations as regards warmth and cold, direct and indirect, we can recreate a little piece of the sky.

Fagerhult's Notor 65 Dynamic

Born out of research on Double Dynamic Lighting Fagerhult launched Notor 65 Dynamic, a luminaire with a clear focus on lighting for people. With diffuse direct/indirect light, combined with directional light from a spotlight mounted on the side, dynamic and natural-like lighting is created. Notor 65 Dynamic is part of our holistic and sustainable approach to lighting, with an emphasis on balance and health.